China's drug watchdog issued a circular on Saturday to remind people of the possible adverse effects of taking allopurinol anti-gout pills.

The circular from the China Food and Drug Administration said that it recorded 485 cases of adverse reaction to taking allopurinol, with 140 severe cases, in 2012.

More than 80 percent of the adverse reactions involved damage to skin, the gastrointestinal tract and the body, it said.

The administration suggested doctors exercise care when prescribing the drug and that patients who experience side-effects from allopurinol should immediately stop taking the medicine.

It also urged producers of the drug to strengthen monitoring of its side-effects and provide guidance in the proper use of the medicine so as to guarantee safety for the public.